Apparatus for self-hooping tubes



E. SCHNEIDER.

APPARATUS FOR SELF HUOPING TUBES APPHCATION FILED MAR- 3|. I919.

1,338,872. F mama ma 4,19

s $HEE\TSSHEET I.

E. SCHNEIDER.

APPARATUS FOR SELF HOOPING TUBES.

APPLICATION FILED MAR- 31. I9I9.

1,338,872. mama May 4,1920.

3 SHEETS-SHEET 2- E. SCHNEIDER.

APPARATUS FOR SELF HOOPING TUBES. APPLICATION FILED mnal. 1919.

1 ,338,872, Patented May 920.

3 SHEETS-S EE 3- x -=d ai B u I- 4;" 4 W I" A UNITED STAllllls PATENT OFFICE.

EUGENE SCHNEIDER,

' nuance,

OF PARIS, FRANCE, ASSIGNOR TO A LIMITED JOINT-STOCK COMPANY OF FRANCE.

SCHNEIDER & 01E, 0]! PARIS,

APPARATUS FOR SELF-HOGPING TUBES.

Application filed March 31,

To all whom, it may concern:

Be it known that LEuoiaNn SCHNEIDER, citizen of the French Republic, and resining at 42 Rue dAnjou Paris, France, have invented new and use 111 Improvements in Apparatus for Self-Hooping Tubes, which invention is fully set forth in the following specification.

In the manufacture by the self-hooping process of metal tubes of great strength having, like gun barrel tubes, an externa longitudinal profile tapering relatively to the axis of the tube, from one end to the other thereof, either continuously or in consecutive steps, it is very important that the deforming pressures applied to the various zones 0 the tube should vary according to the said profile, or more exactly, according to the varying strains to which the said various zones are respectively subjected in the firing of the gun.

This result has been artial extent by the usual processes for self-lumping by consecutive zones. 11 fact it is obvious, if a portion of a tube having externally a continuous taper be divided into consecutive zones, that a tube having externally the inclined profile indicated by the line A- -A in the diagrammatic Figure 1, will give a deformation curve composed of. stepped sections such as a a (L -(i (L a If the pressure that will have been ap plied to the zone Z of the tube is suitable for the mean thickness of the said zone, then obtained only to a the said pressure will be insufficient in the first portion of the said zone, and excessive in the second portion. The same applies to the following 806. This drawback may be remedied to some extent by dividing the tube into a large number 0 zones which will render the operation long and costly.

The improved apparatus of the present invention allows of effecting systematically the seli-hooping" of a tube of any external longitudinal profile. In other words the improved apparatus allows pit varying in a continuous manner according to a given law the internal pressure which is applied in a known way between the internal wa of the tube and the external wall of a mandrel; the said given law of variation coi n ciding very closely with the law of varia- Specification of Letters Patent.

Patented May 4, 1920.

1919. Serial No. 286,502.

tion of the strains to which the tube is subjected at different points of its length.

l or this purpose, the liquid under pressure, which is confined around the mandrel, between a joint at the head and a joint at the end, is compressed by means of a rearward movement imparted to the mandrel, and the liquid, thus compressed, in passing through an axial passage in the mandrel, acts upon a loaded valve mounted in a discharge passage arranged in an outer extension of the said mandrel.

In this manner by an automatic mechanism controlled by the movement of the mandrel, the load on the valve can be varied according to a given law, so that the said valve shall be kept on its seat or shall be lifted by determined strains at determined points of the course of the mandrel.

Since the liquid is confined under pressure in the annular space comprised between the mandrel and the internal wall of the tube, the movement oi the said mandrel may be produced by various means, for instance by the action of a liquid under pressure that exerts a pull or a thrust upon the mandrel. The mechanism r'or automatically regulating the load on the valve by the displacement of the mandrel may likewise be constructed in various ways.

Some constructional forms of the improved apparatus are illustrated by way of example in the accompanying drawings in which 1- Fig. l is a diagrammatic view showing a deformation curve illustrative oi the operation oi the apparatus.

tomplementary Figs. tudinal section partly in side elevation of first constructional form of the invention.

Fig. 3 is a side elevation partly in section, drawn to a larger scale, of the details of the mechanism for automatically regulating the load on the valve.

Fig. 4 is a corresponding 2, 2 are a longiend elevation,

partly in section on the line IV- of Fig. 3.

Fig. 5 is part horizontal section on the line til] upon suitable brackets B. A mandrel (7 is inserted at the beginning of the operation in the tube and so as to extend throughout the entire length of the Liquid under pressure is confined in the annular space F comprised between the internal wall of the tube A and the external wall of the mandrel ll; this space being limited by a fixed closure or joint D at the inner end and a head or joint E movable with the mandrel at its outer end.

he mandrel 0 projects outwardly at the rear. An axial passage 0 formed in the mandrel C and the rearward extension of the latter. establishes communication between the annular space F and a discharge passage c formed in the extension C The passage c is normally closed by a loaded valve.

In the examples shown. the valve consists of a ball G pressed upon its seat by a finger l-l carried by a lever I. that is fulcrumed on a bracket J fixed on the extension C of the mandrel. A heavy disk K is slidabl y mounted on the lever I. lt is clear that the load on the valve (1? will vary with the position of the weight K on the lever I. I t is also clear that the valve (i subjected on one face to the action of the weighted lever I-K. and on its other face to the pressure prevailing in the annular space will remain pressed upon its seat so long as this latter pressure is less than or is equal to the load. and that the valve will rise so soon as the said pressure will become greater than the load.

The mechanism for insuring that the variations of the load on the valve shall follow a given law determined by the move ments of the mandrel. is constructed as tol lows in the illustrated examples.

A cord L attached at one end to the weight K. passes over guide pulleys m m carried by a bracket M fixed to the free end of the extension of the selt-hooping mandrel, and is attached at its other end to a slider N. The latter is held and guided at one point in notches in the extension of the mandrel, and at another point it engages in a guide slot by means of an anti-friction roller n which it carries at the said other point. This slot is formed in a fixed plate P. and preferably in a part 1) fixed to this plate.

It is clear that any outward movement of the mandrel (-(l will produce a corre sponding displacement of the slider N, and the latter which is compelled to follow the guide 0. will act upon thc cord L, and thus pull the weight K along whereby the load on the valve (l will be increased.

The three constructional examples illustrated in the drawings differ from one another merely hy the mechanism for displac ing the mandrel CC In the example shown in Figs. 2. 2 the extension of the mandrel C carries at an intermediate point of its length, a piston C hooped resting working in a cylinder Q into the forward chamber of which the mandrel (7 extends through a stulling box. This forward chamber 1 receives liquid under pressure delivered by a pump R through a pipe S fitted with a cock a. A. discharge pipe T fitted with a cock t, allows of exhausting the liquid from the chamber 9/ into the tank U of the pump.

The liquid under pressure can 'be admitted to the annular space F through a passage 0 that is formed in the mandrel and opens into a union. fitted with a non-return valve or a suitable closing device C The annular space F having been tilled, the union is closed, and the liquid is delivered by the pump R through the pipe S into the chamber 1 of the cylinder Q. The pressure oi the liquid upon the forward face of the piston. tends to move the latter in the rearward direction. This displacement however can take place only at the instant when the pressure in the annular space F and in the passage communicating therewith c\cecds the load on the valve. which load is controlled by the position of the weight K. This pressure can be ascertained by means of a pressure gage V and may be read oft a scale marked on the plate p.

Hy suitable operation of the pump the desired pressure produced in the annular space l may be maintained. and thus the entire length of the internal wall oz" the tube may be subjected. to this pressure for any desired length of time.

Further by suitably operating the pump the pressure in the space F may be raised so as to cause the load d valve to lift. and consequently exhaust liquid through the passage r' (Fig. 3). which will allow the piston to be displaced in the rearward direction. The amount of this disphiccm nt may be regulated very exactly in such a manner that it will produce by the action of the slider X on the ord L. a. determined di plu:c1ncnt of the weight K which will incrcasc the load on the valvc annuint. In this way the tube 3 ill be subje ted For a small fraction of the dis placement oi the piston. to a higher pres sure mrrcspondlug to that ol the new load on the valve. A. suitable operation of" the pinup or of the isolating cock will enable this new pressure to be maiutainml for a deleted length of time. and so on.

lt will pereivce'l that the displm-cments that are in'ipai-ted successively to the piston can also be reduced to any desired ex tent.

in pract ice. the interior of the tube can be subjetc l over zones of continuously diminishc-Il lcngths, to pressures increasing according in a given law. by suitably deter mining the shape oi the guide 0.

ll'hcn the operation finished the by the dcsii-cd,

llo

mission of liquid to the chamber g is shut off by operating the cock 8. This chamber is emptied by opening the cock t, and thus the mandrel C can he returned into its initial position by forcing liquid into the space F through the union G the closing device G of which has previously been opened.

I is a discharge passage opening into the passage T, which can be placed into and out of iommunication with this passage by the operation of a cock to.

in the example illustrated in Figs. 6, 6*, the annular space F is filled through a union titted with a closing device rovided at the end oi the outer extension of the man drel C and into which the passage 0 opens. in the forward end of the tube to be shaped there is screwed a cylinder Q which is connected to the uimp R (not shown) through the passage i. The displacements of the mandrel are produced by the thrust'ot the liquid upon the forward end of the man dr-Jl C.

in the modification illustrated in Figs. 7, I, the invention is shown applied in rombinafion with the apparatus forming the subject matter of an application for patent filed March 31, 1919, Serial No. 286,501, for appa 'atus for the manufacture of metal tubes of great strength by means of internal hydraulic pressure.

T he tube IL is held between two crossheads X X connected together by tie-rods Y. The rear ('rosshcad X serves as an abutmerit vior the rear joint I) limiting the annular space F.

ln the front crosshead X which comprises a differential piston Z similar to the one described in an application for patent dated March 31, 1919, Serial No. 236,4:9l, and serves as a union for the admission of the liquid under pressure, the liquid is admitted into a chamber q, and passes through the axial passage 2 in the piston Z, on its Way to act against the front end of the mail cllfil C.

The [illing ot' the spa' e F is done as in the preceding example, through a union fitted with a closing device provided at the end'of the projecting part C of the mandrel G.

In all the hereinbefore described constructiunal examples. the self-hooping operation is effected in a continuous clearly determined and perfectly adj ustablc manner; t does not require any stoppage for passing: "man the treatment 0? one zone of the tube to the treatment of the next following zone.

What 1 claim is 1. An apparatus for effecting the selfheaping of metal tubes by consecutive tones by means of a liquid under pressure forced into the annular space between the internal Wall of the tube and a mandrel, =1 haracterized by a mechanism that allows of pro-Tuning by gradual displacement of the said mandrel, a gradual increase of the pressure in the said annular space; the said dis placement being automatically limited by a dis harge oi liquid from said space hrough an axial passage of the mandrel opening into a discharge passage formed in an outer extension of the said mandrel and normally closed by a loaded valve whose load is regulated automatically according, to a determined law of variation (corresponding to the variations of the strains to which the various sections of the tube are subjected} by a me'hanism controlled by the displacements of the mandrel and also simultaneously by a guiding cam.

52; An apparatus as claimed in claim l, wherein the loaded valve that limits the rise of pressure in the annular space between the self-hooping mandrel and the tube, is of the stcelyari'l type. the loading: weight being;- slidable along a lever luh-rumed on the outer extension of the mandrel and being connected by a cord to a slider which is guided on the said mandrel extension and also in a cam slot formed in a fixed part.

3. An apparatus as claimed in claim l, wherein the displacenn-nt oi the mandrel is produced by the action of the pressuw liquid upon a piston provided on the outer extension of the mandrel. and worldu; in i-ylinrlcr in which the said mandrel is guided.

4. An apparatus for ctl'ertin r the self hooping of. metal tubes comprising a mandrel longitudinally movable in the bore of the tube being treated and carrying a head in one end of the tube with the mandrel in its initial position, a stationary closure for the other end of the tube. said mandrel forming with the Wall of the tube an annular chamber to receive the fluid-pressure to be compressed therein between the stationary closure and the head moved inwardly by the mandrel, said mandrel having a duct leading from the annular chamber to a discharge outlet to permit the escape of thc fluid-pressure to vary the pressure within said chamber, a valve controlling the discharge outlet, and mechanism actuating the valve to regulate the escape of the fluidpressure to control-the pressure in the an nular chamber during the compressing movement of the mandrel.

5. An apparatus for ellecting the selfhooping of metal tubes comprising a. mandrel longitudinally movable in the bore oi" the tube being treated and carrying head in one end of the tube with the mandrel in its initial position, a stationary closure for the other end of the tube, said mandrel forming with the wall of the tube an annular chamber to receive the fluid-pressure to be compressed therein between the sta tionary closure and the head moved inwardly by the mandrel, said mandrel having a duct leading from the annular chamber to a discharge outlet to permit the escape of the fluid-pressure to vary the pressure Within said chamber, a valve controlling the discharge outlet, mechanism actuating the valve to regulate the escape oi the fluidpressure to control the pressure in the annular chamber during the compressing movement of the mandrel, and a guide calihrated to the var ing stresses to be applied to the wall of the tube controlling the operation of the valve-actuating mechanism to vary the opening and closing of the valve to regulate the fiuid-pressure in the annular chamber to apply the required stresses.

iii. An apparatus for effecting the selt'- hooping of metal tubes comprising a mandrel longitudinally movable in the bore of the tube being treated and carrying a head in one end of the tube with the mandrel in its initial position, a stationary closure for the other end of the tube through which projects the mandrel, said mandrel forming with the wall of the tube an annular chamber to receive the fluid-pressure to be compressed therein between the stationary closure and the head moved inwardly by the mandrel, said mandrel having a duct leading from the annular chamber to a discharge outlet in the outer end of the mandrel to permit the escape of the fluidpressure to vary the pressure Within said chamber, a valve controlling the discharge outlet, mechanism carried by the mandrel to actuate the valve, and a guide calibrated to the varying stresses to be applied to the Wall of the tube engaging the valve-actuating mechanism during the movement of the mandrel to operate said mechanism to actuate the valve to regulate the escape of the fluid-pressure from the annular chamber to vary the application of pressure therein according to the required stresses.

7. An apparatus for effecting the selfhooping of metal tubes comprising a mandrel loiigitudinally movable in the bore of the tube being treated and carrying a head in one end of the tube with the mandrel in its initial position, a stationary closure for the other end of the tube through which projects the mandrel, said mandrel forming with the Wall of the tube an annular chamber to receive the fluid-pressure to be compressed therein between the stationary closure and the head moved inwardly by the mandrel, a cylinder and. coacting piston attached to the mandrel, means for supplying lluid-l'iressure to the cylinder to move the piston and attached mandrel, said mandrel and piston having a duct leading from the annular chamber to a discharge outlet in the outer end of the piston-rod to permit the escape of the fluid-pressure from the annular chamber to vary the pressure in said chamber, a valve controlling the discharge outlet, mechanism carried by the piston-rod to actuate the valve, and a guide calibrated to the varying stresses to be applied to the wall of the tube engaging the valve-actuating mechanism during the movement of the mandrel to operate said mechanism to actuate the valve to regulate the escape of the fluidwessure from the annular chamber to vary the application of pressure therein according to the required stresses.

8. An apparatus for effecting the self hooping of metal tubes having an external longitudinal profile tapering relatively to the axis of the tube, from one end thereof to the other, either continuously or in consecutive steps, comprising a mandrel lon itndinally movable in the bore of the tlfi) being treated and carrying a head in one end of the tube with the mandrel in its initial position, a stationary closure for the other end of the tube through which projccts the mandrel, said mandrel forming with the wall of the tube an annular chamher to receive the fluid-pressure to be compressed therein between the stationary closure and the head moved inwardly b the mandrel, said mandrel having a duct eading from the annular chamber to a discharge outlet in the outer end of the mandrel to permit the escape of the fluid-pressure to vary the pressure in said chamber, a valve controlling the discharge outlet, mechanism responsive to the action of a cam carried by the mandrel to actuate the valve, and a guide having a cumming surtace profiled to correspond to the external longitudinal profile of the tube to engage the cam-responsive mechanism to operate the valve to regulate the escape of the fluirbprcssurc from the annular chamber during the com-- pressing movement of the mandrel.

In testimony whereof I have signed this specification.

EUGENE SCHNEIDER. 

